Cross-source coverage

T1499.002 / ATT&CK

Endpoint Denial of Service: Service Exhaustion Flood

2 rules across 1 source.

From MITRE ATT&CK 19.2

Adversaries may target the different network services provided by systems to conduct a denial of service (DoS). Adversaries often target the availability of DNS and web services, however others have been targeted as well. Web server software can be attacked through a variety of means, some of which apply generally while others are specific to the software being used to provide the service.

One example of this type of attack is known as a simple HTTP flood, where an adversary sends a large number of HTTP requests to a web server to overwhelm it and/or an application that runs on top of it. This flood relies on raw volume to accomplish the objective, exhausting any of the various resources required by the victim software to provide the service.

Another variation, known as a SSL renegotiation attack, takes advantage of a protocol feature in SSL/TLS. The SSL/TLS protocol suite includes mechanisms for the client and server to agree on an encryption algorithm to use for subsequent secure connections. If SSL renegotiation is enabled, a request can be made for renegotiation of the crypto algorithm. In a renegotiation attack, the adversary establishes a SSL/TLS connection and then proceeds to make a series of renegotiation requests. Because the cryptographic renegotiation has a meaningful cost in computation cycles, this can cause an impact to the availability of the service when done in volume.

Tactics: Impact
Platforms: Windows · IaaS · Linux · macOS
Telemetry: WinEventLog:ApplicationWinEventLog:SysmonWindows:perfmonauditd:SYSCALLNSM:Flowlinux:syslogmacos:unifiedlogAWS:CloudTrailAWS:VPCFlowLogsAWS:CloudWatch

How MITRE says to detect it DET0173

Detection Strategy for Endpoint DoS via Service Exhaustion Flood

Windows Analytic 0489

High-frequency, repetitive service requests (e.g., HTTP, TLS renegotiation) originating from a single or small set of source IPs targeting endpoint web services or application ports, leading to exhaustion of CPU or memory on targeted Windows services.

WinEventLog:Application Unexpected spikes in request volume, application-level errors, or thread pool exhaustion in web or API logs
WinEventLog:Sysmon EventCode=3, 22
Windows:perfmon Sustained CPU/memory exhaustion by service process (e.g., w3wp.exe)

Linux Analytic 0490

Excessive inbound HTTP or TLS connections to services such as Apache or Nginx, causing worker thread exhaustion or segmentation faults.

auditd:SYSCALL High frequency of accept(), read(), or SSL_read() syscalls tied to nginx/apache processes
NSM:Flow Sudden spike in incoming flows to web service ports from single/multiple IPs
linux:syslog Repetitive HTTP 408, 500, or 503 errors logged within short timeframe

macOS Analytic 0491

Flood of incoming TLS or HTTP(S) connections to macOS-hosted services (e.g., MAMP, Apache), causing high CPU usage and system unresponsiveness.

macos:unifiedlog Web service process (e.g., httpd) entering crash loop or consuming excessive CPU
macos:unifiedlog Rapid incoming TLS handshakes or HTTP requests in quick succession

IaaS Analytic 0492

Automated or scripted HTTP/TLS flooding from one VM or cloud instance against another service, exploiting compute-based billing or exhaustion of service infrastructure.

AWS:CloudTrail AuthorizeSecurityGroupIngress
AWS:VPCFlowLogs Unusual volume of inbound packets from single source across short time interval
AWS:CloudWatch Sustained spike in CPU usage on EC2 instance with web service role

View on attack.mitre.org ↗

elastic/detection-rules

2 rules

Detection	Severity	Format
Possible Okta DoS Attack	Medium	Elastic TOML
Repeated Stalled TLS Handshakes via ALPN acme-tls/1 Extension	Low	Elastic TOML